
Long story short: I had problems with the Verizon wireless connection between the modem/router upstairs and and a laptop downstairs. All mobile devices worked fine. The signal was acceptable and the laptop connected to the wireless. But I couldn’t get to websites. I’d enter a web address into the browser and it would just spin (and spin and spin).
After three days of dredging through the muck on the Internet, I found this site. I followed the directions to change the network channel. Problem solved, for now at least.